Automatic telegraphy



y 1941- I. w. CONRAD 2,248,522

AUTOMATIC TELEGRAPH! Filed April 18, 1959 2 Sheets-Sheet 1 "I. 5 7INVENTOR.

Fig.5.

Patented July 8, 1941 UNITED STATES PATENT OFFICE 1 2,248,522 AUTOMATICrnpncasrnr Ivan w. comm. Washington, D. 0. Application April is, 1939,Serial No. 268,591

1 Claims. (01. 178-62) The present invention relates to automatictelegraphy' and has for its principal obioct to provide simple,practical, extremely high speed I means for recording at a receivingstation characters selected at a sending station.

Selection of characters at the sending station may be accomplishedmanually as by keyboard, mechanically as by perforated tape, or in anyother desired manner and transmission of s18- nals to the receivingstation may be carried out by radio as well as by wire. Essentially theinvention contemplates the use of electrochemical means for translationof the signals into characters of the alphabet or any other desiredsymbols, as distinguished from such translation by instantaneous sparkdischarge recording means which latter means is the subject ofpetitioner's copend'ing application #164,51'1 filed July 19, 1937.

Prior art discloses the auxiliary use of electrochemical means for thepurpose indicated in conjunction with mechanical means which because ofinertia is necessarily relatively slow in operation, as reflected inLetters Patent #275,339 issued to A. F. Johnson and B. F. Johnson and#316,689 issued to H. Van Hoevenbergh. It is therefore a further objectof this invention to panying' drawings and defined in the appendedclaims.

In the accompanying drawings wherein are illustrated different,non-limiting, practical embodiments of the invention and wherein likecharacters of reference denote corresponding parts in related views:

. Figure 1 is a diagrammatic view illustrating the general principle oithe invention.

Figure 2 'is a diagrammatic view illustrating one practical embodimentof the invention.

Figure 3 is a side elevation of the receiving station mechanismdiagrammatically illustrated in Fi 2.

Figure 4 is a side elevation of the sending station mechanismdiagrammatically illustrated in Fig. 2.

Figure 5 is a view of character formation utilized to give uniformthickness of line to line] printed character.

Figures 6 and 7 are diagrammatic views illustrating alternative forms ofrecording means which may be used in lieu of the recording means shownin Figs. 2 and 3.

Figure 8 is a side elevation of character matrix shown diagrammaticallyin Figure "I.

Figure 9 is a side elevation of an alternative character matrix whichmay be used in lieu of the matrix shown in Figure 8.

Referring to the drawings in detail, A and B designate generally, andrespectively, sending and receiving station mechanisms includingrotatable elements it and ll, respectively, which, in accordance withthe invention, are driven at high speeds and partake of equal, orsubstantially equal, angular increments of movement during any givenperiod of operation of the system. In this connection the synchronous orthe substantially synchronous driving of said elements l0 and Il may beefiected in any suitable manner, as, for example, through the instru-'mentality of synchronous electric motors designated as 12 and i3,respectively, which may derive their power either from a common A. C.source or from separate frequency sources. If said motors derive theirpower from a common A. C. source this A. C. source may, for example, bea 1000 cycle oscillator located at the sending station controllingthetransmitting motor, and by transmission of the 1000 cycle frequency overinterconnecting wires, controlling the receiving motor as well. Saidmotors thus will be synchronized within sufllciently narrow limits forthe successful operation of the invention. If, on the other hand, saidmotors derive their power from separate frequency sources, they must beapproximately synchronized and any error in synchronization may bepermitted to accumulate for one or a series of revolutions but mustperiodically be reduced to zero, which can be done by timing impulses ina well known manner. In other words, while it is not essential to thesuccessful operation of the present invention that the elements l0 andll be exactly synchronized, it is essential that they be drivenapproximately synchronously, either by synchronous motors employingcurrent of suitable high frequency or in some other appropriate mannerin itself forming no part of the present invention and therefore notspecifically shown or claimed.

The rotatable element l 0 of the sending mechanism A carries a pluralityof contacts I l which are spaced angularly about the axis oi rotation ofsaid element and also longitudinally along said element. on the otherhand, the rotatable element ii of the receiving mechanism 3 carries aplurality of characters II which are spaced angularly about the axis ofrotation of said element corresponding to the angular spacing of thecontacts H, but which are disposed in a common plane normal to the axisof rotation of said member.

A plurality of contacts it, one individual to each of the contacts I 4,are provided for cooperation with said contacts I4. These contacts itnormally are disposed out of the paths of rotation of the contacts H,but are movable into the paths of rotation of said contacts ll so as tobe engaged by said contacts l4 responsive to rotation of the elementill. Moreover, said contacts II are disposed in a common plane includingthe axis of rotation of the element II and thereby have fixed positionsso far as concerns rotation of the element ii and the contacts I, sothat no two of said contacts II can simultaneously engage relatedcontacts ll, because of g the aforesaid angular spacing of the contactsII.

The characters I! are, according to one practical embodiment of theinvention, in the form of electrodes and cooperate with an electrode I!which is mounted outwardly of and adjacent to the rotatable element Iiin a fixed position, so that the characters I! successively move pastthe same in suitable spaced relationship thereto as the element iirotates. Thus, by the selection of a contact I! bearing any particulardesignation or character, and by the actuation of properly spaced andwill follow one another in a line on the recording medium.

While some or all of the characters ll may comprise only a singleelectrode for cooperation with the fixed electrode II, it is preferredthat said characters, except in the cases of such of the same as arerelatively small, as commas, periods and the like, shall be comprised bypluralities of electrodes designated as 22, and that th electriccurrents between the fixed electrode l1 and the diiferent electrodes 22shall be distinct from each other, thereby to assure recording or thecomplete outlines of said characters ll. These features of theinvention, as well as a suitable current producing means especiallysuited for. use in the present system is illustrated in1"lga2to4ofthedrawings.

said contact so that the related contact I 4 will engage therewith,element ll may be so oriented that upon engagement of the relatedcontact ll therewith, the corresponding character I! will be in aposition alined with the electrode I! when engagement between thecontacts ll, ll occurs. In this connection any suitable means responsiveto engagement of any given pair of the contacts H, IS with each othermay be provided to effect recording of the related character II at theinstant of its alinement with the fixed electrode i1. One such means isillustrated conventionally in Pig. 1, from which figure it will beobserved that all of the contacts II are connected with the electrode I!by a common line wire it; that all of the contacts I! are connected withall of the characters I! by a common line wire ll; that a suitablerecording medium 2| affected by flow of electric current is interposedbetween the element i I and the fixed electrode l1, and that interposedin the line wire ll is a means 2i for producing an electric currentbetween the electrode l1 and the particular character I! which may bealined therewith when the circuit is closed by engagement of a relatedpair of the contacts I and it. Thus, upon closing of the circuit as aresult of movement of any selected contact [6 into the path of movementof its related contact I! and subsequent movement of the contact ll intoengagement with the selected contact it, a recording of the character I!related to the selected contact I will be effected on the recordingmedium 20 by the electric current between the electrode i1 and the saidrelated character IS.

The recording medium 20 may be in the form of a strip of paper or othersuitable material sensitized or otherwise treated so as to be afi'ectedby the electric current, and any suitable means may be provided foradvancing the same as the characters I! are successively recorded sothat the successively recorded characters will be Referring in detail toFigs. 2 to 5 which illustrate a refined embodiment of the invention ascompared with the conventional Figure l illustration. it will beobserved that the rotatable element II is provided with a series ofcontacts 23 which are angularly spaced apart corresponding to theangular spacing of the characters II: that a fixed contact 2| isprovidedfor cooperation with said contacts 23; that the line wire llconnects all of the contacts I with all of the contacts 22; that a wire2' leads from the fixed contact 24 to the current producing meansdesignated generally as 2 i, and that the line wire ll connects'all ofthe contacts II with said current producing means 2i. It will further beobserved that the rotary element ll carries a plurality of conductorrings 20; that there are separate connections 21 between said rings andthe electrodes 22 of each of the characters II, and that each conductorring 2! has cooperating therewith an individual fixed contact 22.

Of course, some of the characters ll may be comprised by a greater orlesser number of electrodes 22 than other of said characters.Accordingly. there are as many of the conductor rings 28 as the maximumnumber of electrodes in any given character ll so that each electrode ofeach character may have a connection 21 with a distinct ring. Thus, allof the rings 20 may be utilized to provide separate connections for theelectrodes 22 of certain of the characters II and only some of saidrings may be utilized to provide separate connections for the electrodesof other of said characters, depending, of course. upon the number ofelectrodes comprising the difierent characters.

There is an electric current producing means It individual to each ofthe conductor rings 2 to assure a separate current between the electrodeI1 and each of the electrodes 22 comprising any given character beingrecorded. Since, however, said current producing means are, or may beduplicates of one another, only one of the same has been illustrated forthe sake of simplifying the description and to avoid complicating theillustration.

As illustrated in Fig. 2 a preferred current producing means includesessentially a thermionic vacuum tube 2! including filament II, a grid3|, and a plate 22. A source of E. M. 1". I! normally serves to biastube 29 negatively thru impedance 34 to essentially -cut-oif" or zeroplate current condition. However, upon engagement of any given contactII with its related contact ll, said bias will be removed at the instantcontacts 23 and 24 engage, thereby permitting a source of plate E. M. F.ii to force an electric current through the vacuum tube plate circuitwhich as indicated includes contact 28, ring 20, character contact l1,and the plate I! and filament II of the tube itself. Thus since asaforesaid, there is a current producing means II individual to each ofthe rings 20 and therefore to each of the electrodes 22 of each of thecharacters II, it is apparent that during the time interval in whichcontacts l4, It and II, 24 remain closed, there will occur a separatecurrent between the the high speed rotation of the element it anddespite the possibility, and probability, that the contact l4 may travelpast the contact II a number of times while the latter contact is helddepressed. In the present instance the means referred to comprises, inassociation with each of the contacts ll, two channels 4i and 42 (Fig.4)

fixed electrode i1 and all of the electrodes 22 of any character beingrecorded, with the result that a distinct outline of the completecharacter throughout the angle represented by the maximum hunting rangeof the synchronous motors i2 and II. The contacts 23 are, on the otherhand, oi knife-edge type. to assure that a current between the fixedelectrode II and any given character I! will occur only when saidcharacter it is exactly alined with said fixed electrode ll. Thus,straight line recording of the characters ii, as distinguished fromstaggered recording thereoi, is assured.

Since contacts 23 and 24 determine the interval during which recordingcurrent flows through recording medium 20, and because of the finitewidth of these contacts it will be apparent that the characters beingrecorded will move through a small peripheral distance during therecording operation. In order to obtain printed characters of uniformline width, therefore, it is desirable to form the characters as shownin Fig. in such a manner that the width of vertical lines 36 is equal tothe width of horizontal lines 31 plus the trolled gaseous dischargetubes may be used equally as well with proper choice of circuitcomponents and constants, as may also multi-grid tubes.

According to the specific embodiment of the invention illustrated inFigs. 2 to 5, the contacts it are disposed above the rotatable elementI. and are in the form of laterally deflectable fingers depending frompivoted lever arms 3! which are constantly urged upwardly by springmeans 40. Accordingly, said fingers normally are held out of the pathsof rotation of their related contacts H, but are depressible topositions where they will be engaged by said contacts i4 and, whenreleased, will retum to their normal positions. In this connection meansare provided whereby depression of any given contact it into the path ofrotation of its related contact i4 will result in engagement of saidcontact H with said contact It only once even though the contact I maybe held depressed, thereby to assure that the related character it willbe recorded only once despite in the element II respectively alined withand disalined from the contact II when the latter is in its normal,retracted position. The last mentioned channel 42 of each pair isannular, and the companion channel 4| is substantially annular, butinstead of continuing entirely around the element II, is interrupted andis Joined, at its trailing end, as regards the direction of rotation ofthe element ill, with the channel 42 by a diagonal channel 43 in which,at the side thereof toward the channel 4|, is located the contact 14.Accordingly, when the contact it is depressed, its lower end enters thechannel 4| and remains therein until, by rotation oi the element II, itis deflected into the channel 42 by the diagonal connecting channel 43.As this deflection or switching occurs thecontact i4 wipes against thecontact II and provides for closing of the related circuit by engagementof the related contact 28 with the fixed contact 24 at the instant whenthe related character it is exactly alined with the fixed electrode i'I.Obviously, once the contact I I is deflected laterally into the channel42, it will remain therein as long as it is held depressed and cannotagain enter the channel 4| until it has been released and againdepressed. which means, of course, that despite the high rotary speed ofthe-element it, the related circuit will be closed once, and only once,upon depression oi any given contact l8, no matter how long said contactmay be held depressed. In short, the means described insures againstrepeated records of any character I! being made on the recording medium20 as the result of any single actuation of the related contact I.

The arms 38 carrying the contacts ll may be arranged in the manner ofthe keyboard arms of a typewriter, and may be equipped with lingerbuttons or keys 44 having thereon characters corresponding to therelated characters ii. Alternatively, any suitable means other than themeans described may be provided for controlling engagement anddisengagement of the contacts l4, ii. For example, engagement anddisengagement of said contacts may be under the control of a perforatedtape in a manner well known in socalled tape transmission telegraphsystems.

As aforesaid, any suitable means may be employed to effect advance ofthe recording medium 2| as recordation of successive of the charactersit takes place. As illustrated in Fig. 3 this means may comprise a wheelor roll 45 rotatably urged by a spring or other suitable means in adirection to advance said medium 20; an escapement lever 48 cooperatingwith teeth 41 on said wheel or roll, and suitable electro-magnetic means4! cooperating with spring means 49 to actuate said lever 4i to permitsaid wheel or roll 45 to advance the recording medium 20 one step eachtime a recording of any one of the characters It takes place. Thiselectro-magnetie means may derive its actuating energy from a thermionictube, the grid of which is ailected by the recording impulse, as shownin Fig. 2. There may also be provided any suitable means for actuatingsaid sheet or strip advancing means for the purpose of obtaining spacesbetween characters I! and between words or the like formed by groups ofsaid characters, said means including, for example,'a pair of contactsH, II cooperating with a blank space in lieuoi a character II on theelement II.

The forms of the invention illustrated in Figs. 1 to 5 utilizeunidirectional electric current under thermionic vacuum tube control toeffect recording of the characters on the recording medium 2'. Howeverit will be readily understood that other forms of current producingmeans might be employed. For example, the high frequency alternatingcurrent from a Tesla coil or radio frequency oscillator might beemployedas the current producing means 2|. A simplified circuit capableof accomplishing this result is shown in Fig. 6 wherein T represents ahigh frequency transformer coupling the output from oscillating.

tubes I! into recording circuit containing electrode I l, electrodiccharacters i I, and recording medium 20. g

Further it is apparent that instead of utilizing synchronousdistributors at sending and receiving stations, for selection ofcharacters, other suitable nonsynchronous means might be'employed suchas the use of different frequencies, one for each character to berecorded. In Fig. 'l is shown a practical receiving station mechanismresponsive to selection of characters by frequency differentiation, inwhich all mechanical motion whatsoever has been. eliminated with thesole exception of that required to advance the recording medium. In Fig.'L- It and II designate a transmission circuit over which is received arecording signal consisting of a short wave train of frequency 1:.-Normally this signal will be short circulted through impedance 34 andsource of E. M. 1''. II. except in that instance where the impedance 34,being new a tuned circuit, is resonant at the frequency 1:, in whichlatter instance the signal will be impressed upon the grid II of thevacuum tube 2!, which normally is biased to cut-oi! by E, M. I". N. Thesignal will thereupon decrease the effective resistance of tube 29,permitting E. M. 1''. II to force an electric recording current throughelectrode ll, recording medium 2|, recordable character II, and plate 32of said vacuum tube 29. The recordable characters in this instanceconsist of elemental .conducting areas 22 outlining and partiallyfilling the form of the character to be recorded, all elemental areas ofany one character being connected together as at II and to the plate 32of the vacuum tube It. Interspersed with and surrounding the elementalareas or electrodes 2! of any one-character, are placed other elementalelectrodic areas held in a character matrix 52 and connected in groupsto outline all required characters, each group being connected to adifferent vacuum tube or other current producing means. In Fig. 8 areshown one character i! with elemental areas connected as at II and themanner in which other required characters, only one of which is shownfor the sake of clarity, are in effect superimposed in matrix 82although comprising different electrodic elements.

Alternatively, as shown in Fig. 9, character matrix 52 might beconstructed of relatively large electrodic elements 53, none of whichare connected together, each being supplied by a separate currentproducing means, and selectively grouped by any desired type of signalto produce desired characters ii. Areas shaded indicate manner of suchgrouping. For example, each current producing means may be an electronictube SI, designed to energize its related character element upon thereceipt over line ll of a relatively short wave train of an audiofrequency signal. Upon the simultaneous receipt at the receiving stationof a combination of such signals.

each frequency component may be separated by v a suitable filter networkin a well known manner. and caused to energize the related characterelements to produce any desired character.

While the drawings illustrate wire connections between the sending andreceiving mechanisms A and B, it is manifest that such connections mayreadily be replaced by suitable wireless transmitting and receivingdevices associated with the sending and receiving mechanisms A and B,respectively, d that it'accordingly is within thepurview the inventionto employ such devices if desired. Moreover, while only certain specificembodiments of the invention have been illustrated and described toconvey the general concept of the invention, it is to be understood thatthe same is readily capable of various other embodiments within --itsspirit and scope as defined in the appended claims.

I claim: a

1. In a telegraph system, a receiving station mechanism including meansdefining recordable characters in the form of letters, numerals andsymbols, a sensitized electrically conductive recording medium, meansfor advancing said recording medium relative to said characters, meanswith which said character defining means cooperate to supply to saidrecording medium by direct contact conduction a recording current toeifect complete, instantaneous electro-chemical recording ofsaidcharacters on said'recording medium, said means and said charactershaving an unvarying relationship to each other with respect to motion,and means controlling said recording current and the selection ofcharacters to be recorded.

2. In a telegraph system, a receiving station mechanism including meansdefining recordable characters in the form of letters, numerals andsymbols, a sensitized electrically conductive recording medium. meansfor advancing said recording medium relative to said characters. meansfixed with respect to said characters and with which said characterdefining means cooperate to supply to said recording medium by directcontact conduction a recording current to effect complete, instantaneouselectrochemical recording of said characters on said recording medium,and means controlling said recording current and the selection ofcharacters to be recorded.

3. In a telegraph system, a receiving station mechanism including meansdefining recordable characters in the form of letters, numerals andsymbols, a sensitized electrically conductive recording medium, meansfor advancing said recording medium relative to said characters.electrodic means continuously uniformly movable relative to saidcharacters and with which said character defining means cooperate tosupply 'to said recording medium by direct contact conduction arecording current to effect complete, instantaneous electrochemicalrecording of said characters on said recording medium, said electrodicmeans and said characters being continuously uniformly movable onerelative to the other, and means controlling said recording current andthe selection of characters to be recorded.

4. A telegraph system as set forth in claim 3 in which the electrodicmeans and the character defining means have rotary motion one relativeto the other.

5. In a telegraph system, a receiving station mechanism, comprisingelectrochemical character recording means including recordableelectrodic characters in the form of letters, numerals, and symbols,each comprising a plurality of electrodes; a recording medium; means foradvancing said recording medium relative to said characters; cooperativemeans, including an electrode, fixed in relation to the electrodes ofsaid characters and with which the electrodes of said characterscooperate to efiect complete instantaneous recording of the electrodesof any given character by the electrochemical action of a recordingcurrent conducted to said recording medium by direct contact of theelectrodes of said characters and said cooperating electrode therewith;a separate recording current producing means for each electrode oi. eachof said characters, said character electrodes having an interfittingrelationship to each other so that "certain of the same are common todiiIerent characters, and means controlling said recording current andthe selection of character electrodes to be recorded.

6. In a telegraph system, a receiving station mechanism includingrecordable electrodic characters in the form of letters, numerals andsymbols; a sensitized, electrically conductive recording medium relativeto said characters; means for advancing said recording medium;cooperative means including an electrode fixed in relation to saidelectrodic characters and with which said electrodic characterscooperate to effect complete instantaneous recording of the same by theelectrochemical action of a recording current conducted to saidrecording medium by direct contact of said electrodic characters andcooperative electrode therewith; and means controlling said recordingcurrent and selection of characters to be recorded; said electrodiccharacters each comprising a plurality of electrodes connected togetherand further connected to a separate recording current producing meansindividual to each character, the elecrodes comprising each characterbeing separate and distinct from the electrodes comprising each othercharacter and certain of the electrodes comprising certain of saidcharacters being disposed within the outlines of certain other of saidcharacters.

7. In a telegraph system, a receiving station mechanism comprisingrecordable characters in the form of letters, numerals and symbols; 9.recording medium; means for advancing said recording medium relative tosaid characters; means for recording said characters on said medium;said last mentioned means includin means whereby said characters andsaid medium have motion relative to each other during recording of saidcharacters, and means to assure that recorded characters possess uniformline width regardless 01' relative motion between said recordablecharacters and said medium during interval in which recordation orcharacters occurs, said last mentioned means comprising recordablecharacters of such line width that the sum of the displacement relativeto said recording medium of any given point on a character beingrecorded during the recording interval, and the line width of saidcharacter at said given point measured in the direction or said relativedisplacement, is a constant.

IVAN W. CONRAD.

